I'm not great at writing reviews, but I'm bored right now and I thought I'd take the time to "honor" the RE0's. I've bought/sold/heard many IEM's in the past, stuff like: IE8, W3, PFE, SE530, TF10, X10 etc. Before the RE0's went on that $99 sale, I came to the conclusion that the W3's were the IEM's for me, X10 and SE530 came in a close second, but anyway, my point is, I was quite satisfied with the W3's until I decided to give the RE0's a shot. At first, I was really missing the bass of the W3's, the RE0's sounded a bit thin compared to them. I was disappointed but I didn't give up on them. I burned them in and kept listening. Eventually, whether it was my mind adjusting or my taste changing, I realized how refreshing the RE0's sounded compared to the W3's, it was like a splash of cold water after walking through the desert. I was no longer missing the coloration of the W3's, I felt like the RE0's were the most natural sounding IEM's I've ever heard. Highs extend effortlessly with no signs of fatigue or harshness. Female vocals really shine. They may disappoint bass-heads, but for anyone who strives for true audio reproduction, this is the IEM for you. The bass is there and it's accurate, it's quality, but it just lacks that visceral impact that some IEM's provide (IE8 comes to mind). They can really rock out too, quite a dynamic sound with great PRAT, instrument separation is fantastic and the timbre is spot-on.

In conclusion, for me, this was the IEM that stopped my search/interest in the next FOTM. And what shocks me the most is, it's pretty much 1/3 the price of all the other IEM's I've tried. Incredible value @ $79, actually, it's an absolute S T E A L, I highly doubt you can find anything better for the price, or even double/triple the price. Of course, YMMV, but this is my experience.

I’ve already written a great deal on the RE0s but I don’t consider any of it a formal review in the traditional sense. If you’ve read my previous writing about the RE0s, you should know that I am positively enamored by them. In the few weeks since I received them, they have quickly become my preferred listening devices when I sit down with my laptop or iPod and listen to music. After putting them through their paces for 200+ hours and listening to the sound signature evolve and mature in that time, I finally feel that I’m ready to give the RE0s the review they deserve. So, without further ado, read on for my full review of the HiFiMan RE0 in ear monitors.

The RE0s come packaged in a small, clear plastic clamshell box. The design is unobtrusive and eye catching, showing off the IEMs flanked by the three pairs of silicone single flange tips. Included accessories range from the aforementioned three pairs of single flange silicone tips, two pairs of small and large bi-flanges, five pairs of replacement filters and a shirt clip. Overall, this is a decent accessory package but I would’ve been happier if a soft or hard carrying case had been included with the package. I guess you could argue that the case the RE0s came in could be used to carry them around in a pinch but it’s just slightly too big and bulky to fit very comfortably in a pocket.

Design and Build Quality

Right off the bat, the similarity to the V-Moda Vibes is immediately apparent. The housing is made of metal, painted black with a matte finish instead of the high-fashion polished aluminum look and feel of the V-Moda Vibes. The metal design inspires confidence in terms of long and short-term durability in that they feel sturdy and resilient without being too heavy or too light. Extending down from the casing is a long strain relief which is soft rubber in texture and adds to the durability and protects the cable as it enters the housing. The cable also terminates in a properly relieved L-plug which is new in the current revision of the RE0s.

The cable itself is relatively heavy, fairly thick and very soft and pliable. It seems durable enough to withstand a fair amount of abuse. One issue I have with the cabling of the RE0s is that they transmit a lot of cable noise. Wearing them straight down while walking or performing any kind of activity that causes the IEMs to rub against your clothing, will result in microphonic noise being transmitted into your ears. It’s annoying and distracting to be sure and using the included shirt clip and wearing them over-the-ear is practically required if you plan on walking with these.

These feel like they will be able to withstand normal amounts of daily use and abuse for a long period of time. I do wish these came with a carrying case of some kind to protect them while on the go and naturally, it’s expected that you’ll want to protect your investment. I would advise investing in a carrying case of some kind to protect them if you plan on carrying them around.

Comfort and Fit

The housings of the RE0s are very small and light and, as such, you’ll barely feel them while they’re in your ears. For me and my small ear canals, the small black tips were best for me but now, I use a pair of small tips I sourced from a pair of V-Moda Vibes which I find to be a bit softer and thus more comfortable. With all of the various eartips supplied with the RE0s, I’m sure that most users will be able to find a pair that work for them.

Sound Quality

Let me preface this by saying that these are the best sounding IEMs I’ve ever heard. Nothing I’ve ever used comes close to matching the RE0s in terms of clarity and transparency, bass and treble extension and micro level detail. These are a highly resolving pair of IEMs and as such will be highly revealing of flaws in your source material. I would not recommend using these with 128kbps music files or any other poorly recorded music, as these will make the flaws in those files stand out so much more. On the other hand, because they are so highly resolving, they allow great recordings and high bitrate files such as 320kbps MP3s and FLAC files to shine.

The RE0s are a very neutral pair of IEMs across the board and offer very little in the way of coloration to the music being pumped through them. These are highly transparent and allow you to hear music mostly as the artist intended, without adding any degree of warmth or coldness that isn’t actually present in the piece itself.

The midrange is fairly recessed but lively and very clear. Both male and female vocals are full-bodied and natural sounding and, across the board, instruments just sound great. The biggest strength of the RE0s is their endlessly extended and exceptionally clear and bright treble. Highs are forward and sparkle with just a touch of warmth without a hint of sibilance. These have the best highs I’ve ever heard in an IEM and should please just about anyone looking for a great high end response.

Low end response is perhaps the weakest aspect of the RE0’s sonic presentation but even then, it’s not at all bad. Bass is very detailed and natural sounding but what it lacks in is body. It just doesn’t have quite enough “oomph” to my ears and as a result makes the entire sound signature somewhat thin. Extension is very nice as well, as you can detect bass notes down to 20 Hz, even if those notes aren’t particularly powerful.

Soundstage and imaging are both good as well. The soundstage is of average size and depth, with great instrument separation and decent imaging.

The RE0s don’t necessarily need an amp, despite their relatively high 64 ohm impedance but respond very well to the extra juice. The soundstage widens a bit, dynamics improve and the bass improves a bit in terms of fullness. These also respond well to amps with a bass boost feature such as the inexpensive Fiio E5 and the JDS Labs CMoy BB, which highlight the great low end detail and sub-bass extension the RE0s possess.

Conclusion

Without a doubt, these are the best IEMs I’ve ever heard. These really make my music collection come alive and are very entertaining to listen to for long stretches. They let the music sink in slowly if you’re reading a book, doing homework or anything else that requires concentration while also allowing you to tune into the finer details of the music and really immerse yourself in the music you hear. For the current asking price of $80 plus shipping from Head-Direct, you really can’t go wrong with the RE0s. While these probably won’t satisfy bass-heads (at least without a bass boosting amp), these can easily compete with IEMs three to four times their price and are an absolutely phenomenal value for the price. I highly recommend these to budget conscious audiophiles who are interested in neutral and, above all, excellent sounding IEMs.

These are easily the best earphones I've ever heard. They out-perform both of my older sets of cans. Admittedly, they're older headphones, but they're AKG and Sennheiser cans that were worth equivalent money or better than the Re0s so, to me, that's impressive!

The Head-Direct and Hi-Fi Man brands are one and the same so don't be thrown by the different references. If it says Re0, it's the same earphone regardless of which brand you read on the review.

The Re0s are a 9mm dynamic driver canal phone. They are a simple and plain design which belies their spectacular sound.

The specs don't really jump out:

9mm dynamic drivers with neodymium

64 Ohm impedance

100 dB/1mW sensitivity

15 - 22,000 Hz range

Sound Quality

I used to work for a hi-end audio-visual manufacturer and one of the key lessons from my time there was that the first impression of an audio or visual source is not accurate. The TVs and speakers that we often go for first are the most dynamic or bright, but almost never the most accurate. These dynamic sources seem exciting at first, but will quickly become tiring. The natural, true-to-life sources seem dull, flat and boring at first, but in time our body adjusts to these (and we stop comparing them with other sources) and we discover the subtleties and balance that make them truly special. The Re0s are one of those balanced, natural sources so give them a chance when you first get them. Get to know them so they can knock your socks off when you least expect it!!

The sound from the Re0s is pretty close to perfect. Detail is amazing, mids are realistic and bass is present, but never over-stated. The sound is smooth, detailed and never harsh.

On first listen, I was concerned that the Re0s lacked bass. Some reviews also speak about the bass being a bit thin, but I played around with the different tips provided (5 options!) until I found the right ones. That fixed it and the bass has been beautiful ever since. Coincidentally, this happened after some burn-in time so I can't rule out the benefit of burning these in - the debate rages on!

Design

If there's one negative of the Re0s it's their design from a purely aesthetic perspective. In terms of fit and performance, they're right on the mark, but they look pretty cheap. That doesn't mean they aren't well put together. The bodies are metal and the rubber used in the cable is high quality. The plug is high quality and the insulation is tapered so it'll fit any source you can think of. The cable splits at a classy metal junction and the sliding ring to hold the separate L/R cables together is also metal so it's not like they actually ARE cheap, quite the opposite, but they LOOK cheap.

The phones themselves are simple, black painted metal with touches of polished metal. On the back of the phones is a circular area of bare metal and the finish here looks a bit rough, but it doesn't actually effect the earphones so look past that and be pleased that the Re0s are a sleeper that no-one will be drawn to steal (unless they've listened to a pair ).

Comfort

I'm a novice with canal phones, but I find these comfortable. It's important though that you find the right tips. The Re0s come with S, M & L black rubber tips and S & L twin-flange tips. Play around until you find the right one and pay attention to the bass quality. When the bass and sound isolation are best, you've got the best seal.

Something to note here is that pushing canal phones into your ear can create a pressure lock of sorts in the ear canal. Not only can this be uncomfortable, it can also affect the performance of your eardrum and possibly the phone. If you feel pressure, wiggle the earphone until the pressure equalises and then judge the sound and comfort.

Isolation

Again, as a canal phone novice, I have no real comparison, but these block out plenty of noise when I'm on the train or riding my bike so they're good enough for me.

Source Notes

I was concerned when I bought the Re0s that they may not work effectively on my iPod or iPhone without amplification. They do. I love great sound, but I'm realistic about it and don't want to carry around excess equipment. The Re0s are a perfect way to achieve outstanding sound from a simple source like the iPod... BUT... you won't want to use any equaliser adjustments on basic sources (like iPods). Basic sources don't have the amplification circuits to really handle any tweaking of the sound.

Before I got the fit of the Re0s right I was playing around with the bass boost on the iPod and I forgot to switch it off. Later in the week I was disturbed to hear all sorts of sound quality issues from my iPod and actually thought the amplifier circuit was giving up the ghost (it's an old pod). I suddenly realised my mistake and switched off the bass boost - perfect!

The Re0s WILL show up any poor recordings and sources, but the good news is that their magnificently balanced sound means that you shouldn't have to apply modifications to the sound - just enjoy it as the artists intended.

Overall

These phones have everything right where it matters. They've outperformed everything I've listened to, even phones worth more $$$. They don't look flashy, but they sound spectacular (if you get the fit right). I'd recommend these to anyone.

I really wish the RE0s lived up to their promise. They do sound really good, but they are clearly the product of cost-cutting. I bought a pair, and within a month, one of the buds was cutting out, and soon there after failed completely. I had them RMA'd, and within 6 months, the replacements began to fail (the adhesive that keeps the speaker part glued in to the casing is failing or has failed on both buds). I would have paid 50% more for these headphones and been happy if they stayed in one piece, but now, I wouldn't be happy if they had cost 50% of what I paid.

tl;dr great headphones crippled by terrible materials and quality control.

You don't need another review about how good these sound. But I had two pairs, both of which lasted only a couple of months before one ear went dead. I was keeping them wrapped around my ipod in my bag but wasn't abusing them. So either I had shocking luck or these phones are a bit fragile.

I had the Re0 since Late Feb and I love it! I was hunting for a bargain at first and when I received mine I was like"meh" then after 50 hours the bass starts to kick in and mids is much warmer now after 200 hrs I ditched my full can(srh840) and removed the filter, much more sharper but that is just me. I would highly recommend this to anyone who is looking for the best item under $100 and if you dont like the original tips try the sony hybrid tips($10 at sonystyle).

Congratulation on the success and a big THANK YOU to HiFiMan for this exceptional earphone and I do suggest a less microphonic cable and maybe offer a wider color selection (Sorry I am baked :)

The are SO many things the RE0 does amazing well. Treble extension is crazy without any graininess or fatique. Bass extension is also very low, but the bass body is probably too polite. The bass decays too quickly to give a sense of bass warmth and body, and the bass impact is too tame.

But this bass response is from the RE0 unamped. Suprisingly, a simple little $25 Fiio E5 with it's bass boost really improves the RE0 -- even more so than my $120 iBasso T3 (no bass boost on it). The E5 gives a slight bass boost and a very slight treble cut (to help the sense of the bass boost) -- but the treble cut does no harm at all to the awesomeness of the treble response, extension and smoothness.

The one thing the RE0 does lack is a sense of space around instruments. It's not that it gets jumbled in busy music passages -- the instrument layering is just a bit 2-dimensional, a bit flat. But that's a technical aspect that many people won't recognize nor be bothered by. It doesn't prevent me from enjoying the RE0.

Cons: Low end weak, sound isolation is not the greatest, rubber tips but no foam offered

Well I searched and searched everywhere I could to find a replacement for my Shure E2c's and with a little skepticism I went with the HiFi Re0s. I couldn't wait to try them out. I didn't really believe in the burn in time for buds but to my dismay these needed a few hours to really get the full body sound. I also had to replace the rubber tips with Comply foam from my local Radio Shack for a mere $15. So total I have spent $99 on these and I am happy to say I will be looking to purchase these again when need be. I was really worried I wouldn't find what I came to really enjoy from my E2c's. The E2c's had great bass and great sound isolation. The Re0 have a more full natural sound for less money. So i rated the value high but the isolation low because of what the E2c's provided. Comfort is only 3.5 because of having to go out and purchase after market tips. They are now stellar and fit better then my E2c's did, which I thought could never happen. Audio quality is only a 4 because I know there are better buds but for more money. The design is small and compact and so far seem durable, but the only worry is the cord is your basic quality. These are very affordable even for the average listener. These come highly recommended from me but who am I?

Head-Direct RE0 In-ear Headphones, with the nick name "Kylin", are one of the best In-ear headphones in the world.
* In-ear Design, 15-20 dB isolation
* The best dynamic drivers
* Leather Packing Box
* Smooth and transparent middle range.
**Current RE0 cable was made by PPE material, which is much more reliable than the old version fabric cable. The new L-shape miniplug is much better than previous plug, too.